In order to start search in the Norwegian archives the following information:
Your grandfathers name and date of birth, if you have found his wedding records, then you would most likely have his fathers name.
Your Great aunt Trina Storeide Murray - I guess her maiden name is Storeide, do you have date of birth and her fathers name - she might not have used Storeide when emigrating, do you know when she emigrated. Is she your grandfathers sister?
Lenseth/Lonseth - who used this last name.
Your grandmother Mathilda Hansen, do you have her date of birth and her fathers name.
Your grandmother Erika Elton, do you have her date of birth and her fathers name.
Death certificates will often reveal the name the father/parents of the deceased.
If you have names of sibling of your grandparents or other facts that would be helpful in order to identify the correct families.